While anti-retroviral therapy (ART) is successful in controlling virus replication in HIV-1 positive individuals, the virus is suppressed rather than trly eradicated. Toxicity and drug resistance associated with long term ART remain to be a challenge for effective AIDS therapy. Thus, development of new therapeutics with novel mechanism of action may further improve current ART. Our long-term goal is to identify novel anti-HIV drugs that can eventually eradicate the virus in infected individuals. As a step toward this goal, we have identified a class of quinolizidines, including aloperine, which inhibit HIV at -5 uM by blocking the viral entry. Aloperine has been shown to have anti-inflammatory activity, which may also work to relieve immunopathogenesis associated with HIV-1 infection. Our preliminary structural optimization has yielded aloperine derivatives with approximately 10-fold increase in anti-HIV-1 activity. Based on these promising results, we hypothesize that more potent anti- HIV quinolizidines with anti-inflammatory activity can be obtained through rational drug design. The goal of this project is to improve the potency of aloperine and to establish the pharmacological profiles, such as mechanism of action and in vivo efficacy, which are essential for further drug development. The following Specific Aims will be carried out to test this hypothesis and achieve our goal in identifying promising anti-HIV agents: (1) to determine the molecular mechanisms of action of the anti-HIV-1 entry activity of quinolizidines. Our approach to achieve this aim includes photoaffinity labeling of the drug targets and characterization of HIV-1 mutants resistant to the quinolizidines; (2) to identify potent quinolizidine derivatives through lead optimization. Our approach to achieve this goal is to optimize both the functional groups and the quinolizidine scaffold to obtain derivatives with low nM anti-HIV-1 potency; (3) to establish the anti-HIV-1 profiles of aloperine derivatives using in vitro and in vivo models. Aloperine (MW=232) is a natural product found in several common plant species and can be obtained by total synthesis. Aloperine has been shown to have optimal PK profiles and to be effective in animal models of inflammatory diseases. Thus, it is an attractive hit for lead optimization. Upon completion of the proposed study, we expect to identify optimized aloperine derivatives with low nM potency and in vivo efficacy against HIV-1. In addition, this study will determine the potential beneficial anti-inflammatory effect of aloperine on immune activation associated with HIV-1 infection and establish structure-activity relationship profiles for future structural optimization for potent anti-inflammatory activity. Such compounds with the dual modes of action may become a useful addition to ART, and have potential to reduce inflammation associated with HIV-1 infection.